Cosmogenic 26Al/10Be surface production ratio in Greenland

• Published in: Geophysical Research Letters
• Main Authors: Corbett, LB, Bierman, PR, Rood, DH, Caffee, MW, Lifton, NA, Woodruff, TE
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union 2017
• Subjects: Science & Technology; Physical Sciences; Geosciences; Multidisciplinary; Geology; BE-10 PRODUCTION-RATE; PRODUCTION-RATE CALIBRATION; NUCLIDE PRODUCTION-RATES; LAST GLACIAL MAXIMUM; IN-SITU; ICE-SHEET; WESTERN GREENLAND; NORTHWEST GREENLAND; EROSION RATES; ARCTIC CANADA; Meteorology & Atmospheric Sciences; MD Multidisciplinary; Arctic; Canada; Greenland; Ice Sheet
• Online Access: http://hdl.handle.net/10044/1/45628; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000396115000020&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202; https://doi.org/10.1002/2016GL071276

The assumed value for the cosmogenic 26Al/10Be surface production rate ratio in quartz is an important parameter for studies investigating the burial or subaerial erosion of long-lived surfaces and sediments. Recent models and data suggest that the production ratio is spatially variable and may be greater than originally thought. Here we present measured 26Al/10Be ratios for 24 continuously exposed bedrock and boulder surfaces spanning ~61–77°N in Greenland. Empirical measurements, such as ours, include nuclides produced predominately by neutron-induced spallation with percent-level contributions by muon interactions. The slope of a York regression line fit to our data is 7.3 ± 0.3 (1σ), suggesting that the 26Al/10Be surface production ratio exceeds the commonly used value of 6.75, at least in the Arctic. A higher 26Al/10Be production ratio has implications for multinuclide cosmogenic isotope studies because it results in greater modeled burial durations and erosion rates.